The present invention relates in general to vehicle clutches and in particular to improved structure for a diaphragm spring clutch.
Clutches are well known which are adapted to selectively connect a driving member to a driven output member, typically for together within a vehicle. Within such a clutch, some sort of spring mechanism is typically used to the components thereof toward an engaged position, the output member is frictionally engaged by the input member. Frequently, a plurality of coil springs is provided for this purpose. Such coil springs are generally disposed in pairs about the axis of rotation of the clutch between a cover for the clutch and an axially movable release retainer. The combined force generated by these springs urges the retainer away from the cover toward a flywheel. The cover and the flywheel are connected together and are rotatably driven by the engine of the vehicle.
Between the retainer and the flywheel, a pressure plate is disposed. The pressure plate is axially movable with the retainer by means of a lever system. A driven disc is interposed between the pressure plate and the flywheel. The driven disc is connected for rotation with an output shaft. The springs cause the driven disc to be frictionally engaged between the pressure plate and the flywheel until the urging thereof is overcome by a releasing force applied by the operator of the vehicle through a conventional mechanism. The releasing force moves the retainer and the pressure plate away from the driven disc, thereby releasing the frictional engagement thereof.
The plurality of coil springs may be replaced by a single diaphragm spring, also known as a Belleville spring. The diaphragm spring is formed generally in the shape of an angled annular washer. The diaphragm spring is disposed between the cover and the release retainer of the clutch, as are the coil springs described above, and functions in a similar manner to urge the components of the clutch toward the engaged position The use of a diaphragm spring is desirable because it reduces the number of parts in the clutch. The use of a diaphragm spring is also desirable because the load/deflection characteristics thereof can be adjusted.